Spirocyclic polycyclic polyprenylated acylphloroglucinols from Hypericum henryi and their anti-inflammatory activity.

Five undescribed spirocyclic polycyclic polyprenylated acylphloroglucinols, hypehenols A-E (1-5), together with eight known analogues were isolated from the aerial portions of Hypericum henryi. Among them, compounds 2 and 3 feature a novel 5/6/5/7 tetracyclic system. Their structures were identified by comprehensive analysis of spectroscopic data. The absolute configurations of compounds 1-5 were determined by experimental and calculated electronic circular dichroism (ECD) spectra, along with the Rh2(OCOCF3)4-induced CD method. The anti-inflammatory activity of all compounds was assessed in lipopolysaccharide (LPS)-induced RAW264.7 cells. Compounds 1-6 exhibited inhibitory activity on nitric oxide production, with IC50 values ranging from 10.29 ± 0.59 to 20.08 ± 2.73 μM. Further research indicated that compound 5 could downregulate the expression of TNF-α and IL-6.